This games fighting system is very different than most MMOs and its also my favorite part. Its a turn based combat system that relies heavily on tactics. It plays kind of like chess except theres a bit more luck and oh course every class has special abilities that will effect the play style. You need to have a plan for your character from the start if you want them to end up any good. I remember my first character failed very badly because I was such a noob. Now I've learned how to play and my current character is on the road to success.
Every class has several potential builds. Some are very clear if you look at the spells (ie Strength Iop) and some can be more creative which can also surprise enemies not used to fighting a player like that (ie strength xelor). I myself am an agility sram. Most srams are strength or agi/str hybrids but I went the pure agi route mostly because I can use a spell "Con" to do nice damage from afar and steal money. Plus Agility Srams have a very nice selection of daggers to choose from which is the reccommended weapon for all srams with bows as an alternate.
Unlike a game like WoW where level determines everything dofus leaves a large portion up to tactics and strategy so while a higher level character certainly has an advantage it is not a surefire guarantee that they will win.
Dofus is different but fun. The world of Amakna is vast and has plently of places for characters of all levels to fight, explore, and have fun. Play Dofus if you want a fresh take on MMO's